Experimental Study on Properties and Microbial Methane Oxidation Capacity of Biochar-Modified Silty Soils

Biochar is mostly made from agricultural and forestry wastes. It has the characteristics of high organic matter content, porous structure and high adsorption, so it is widely considered as an amendment to affect soil properties and enhance the growth of microbes. In this study, rice straw biochar and wood chip biochar were added into the silty soil, and the methane oxidation capacity of the two kinds of biochar-modified soils was studied through batch experiments. For the two types of biochar-modified soils tested in this experiment, there was optimal water content and biochar content to maximize the methane oxidation ability. The results showed that for biochar-modified silty soils with biochar content (Bc) of 20–30%, the maximum methane oxidation rate was 3–4 times that of silty soil. Wood chip biochar-modified soil has a higher methane oxidation capacity because wood chip biochar has a larger specific surface area, higher organic matter content and lower pH compared with rice straw biochar. This study could provide a reference for the design of landfills.